1. Field of Invention
This invention relates to an electrical igniter mechanism for use in a rocket motor apparatus adapted to tow a load fastened to the rear end of a rocket motor by means of a tow line.
2. Background of Invention
Igniter switch mechanisms especially ones for use in rocket motors requires precise timing, in many instances, to positively ignite the propellant for powered rocket flight at a given time after a sequence of operations. This is especially the case where a requirement is to extract an air crew member, by powered rocket flight from an aircraft, by ignition of the rocket motor a predetermined time after its launch. These requirements demand exact timing to prevent either rocket malfunction or erratic powered flight of the rocket either of which could cause serious injury to the crew member or damage to the load.
Due to the need in recent years for lighter, simpler and more effective rocket motors for preforming a variety of tasks, for example carrying a line, towing a load or extracting a crew member to a safe distance from a disabled aircraft, it has been necessary to provide the rocket with a safe, simple economical ignition system that makes positive electric contact under all types of environmental conditions.
Prior art techniques have used relatively complex mechanical igniter features to provide safe operation since most rockets require only very low pull forces to cock and release a firing pin to ignite the rocket propellant. The devices are usually not activated by the tow line but by some other means remote from the rocket motor. To accomplish ignition may require the use of additional lanyards, powder trains or the like, which could affect ignition reliability. This is especially true in situations where there is a need for positive rocket ignition after a sequence of events taking place within a given time period during rocket motor launch and before rocket powered flight.
The present unique electrical ignition mechanism is a positive closing electrical switch device that depends on a predetermined pull being exerted by the tow line before ignition action can take place. The mechanism overcomes the inherent disadvantages of present complex mechanical rocket igniter systems by providing a mechanism that is simple, foolproof in operation and requires a minimum of parts